New processors power embedded systems

Advances in embedded systems technology make it possible for systems integrators to bring new power in ever-smaller profiles to defense systems and deliver increasingly powerful applications. But first, they need to get past budget constraints.

“Our end customers are really pushing for low cost — we always start with that, the lowest-cost products,” said John Van Doren, staff engineer at Dynamics Research. “The only time [customers] are willing to spend more is when we can provide more computing power and more communications ability into a single slot than what they've had available before — often more than even just a year ago, in fact.”

New multicore general processors are making their way onto embedded systems and even more advanced field-programmable gate arrays (FPGAs) — silicon processors that can have their configuration reprogrammed based on the mission — that can be integrated with hard-core general processors. Those systems are making it possible to run symmetric multiprocessing applications on a board in a control console, navigation system, sensor or weapons system.

They're also making it possible to more fully move entire desktop-like operating systems into the embedded domain — bringing PC-like features down to consumer electronic devices, cell phones and, potentially, devices for the battlefield. Processor manufacturer Intel's recent acquisition of embedded operating system vendor Wind River, maker of the leading multicore-capable real-time operating system VxWorks, signals the arrival of the convergence of networked applications and embedded systems.

Open source's role

The power of new embedded platforms also makes it possible to use commercial operating systems and open source in the embedded realm. Systems based on Linux, such as the Future Combat Systems' System of Systems Common Operating Environment, are becoming more pervasive in operational environments. Meanwhile, embedded Linux is making its way even into some robotics applications, such as iRobot and John Deere's R-Gator unmanned ground vehicle in use by the Defense Department for perimeter patrols and other tasks.

“Linux is getting widespread adoption,” said Stephen Blackman, director of business development for aerospace and defense at embedded operating system vendor LynuxWorks. But he said Linux is not yet ready for the most intensive embedded systems applications. “The issue is Linux is not quite there from a hard real-time performance standpoint. So where people are going for optimal performance and optimal throughput, they're tending not to use the Linux platform yet.”

The conservative nature of embedded systems development is most heavily present in the realm of safety-critical systems, which are real-time embedded applications that protect human lives. That's a realm Blackman said Linux will likely never play in.

“Our customers are using our systems in safety-critical applications, like avionics, guidance systems, control stations for unmanned vehicles, in unmanned vehicles and satellites,” Blackman said. “Those systems need to be evaluated against safety standards such as DO-178B, [a Federal Aviation Administration-mandated standard for avionics systems], and ARINC 653, [the Avionics Application Standard Software Interface, a specification for real-time operating systems in avionics and other systems]. And Linux is just too big to be used in those areas. Just like nobody wants to get in a plane that Microsoft Windows is flying, Linux might be better, but it's cost-prohibitively too big to be evaluated to those safety standards.”

The standards around safety-critical systems are so exacting, Blackman said, that no one has yet had a multicore system certified. “Most of the safety-critical avionics still use a single core because the FAA hasn't approved anyone with a multicore solution,” he said.

However, perhaps the biggest demand on embedded systems is for them to comply with information assurance standards, such as DOD's Directive 8500.1 and 8500.2. “From a DOD standpoint, the biggest trend is probably security,” Blackman said. “It's how to implement and support information assurance. That's the key element, not just from a cyber warfare standpoint, which is very important, but overall in the embedded systems, as well.”

When multicore technology, safety-critical systems and information assurance run against one another, that creates a significant technical challenge, said Blackman and other industry observers. “When you have the union of those pieces and you have different people with different requirements, that's a challenge,” Blackman said. “There are active groups working on this issue. The [Air Force Research Laboratory] has various programs looking at how to do multicore, safety-critical and security all in the same system.”

Life cycle extensions

That problem needs to be solved, especially with the increasingly networked nature of embedded computing. Enforcing information assurance across all embedded systems will inevitably mean retrofitting many systems because most embedded systems have historically operated without an information assurance review, according to industry experts. And given the long life cycle of many deployed systems, waiting for them to cycle out of inventory will mean potential gaps in security for a long time.

Meanwhile, information assurance isn't the only motivation for retrofitting embedded systems. With tight budgets, upgrading existing embedded systems with retrofitted capabilities is increasingly attractive, especially with the recent cancellation of several large systems, including the vehicle portion of the Future Combat Systems program. And with Coast Guard, Reserve and National Guard units bearing more of the operational burden, extending the life of older systems and extending their capabilities is now mission critical.

Rather than rip and replace entire systems, Van Doren said, half of his team of about 30 engineers at Dynamic Research apply the existing architecture of systems and give them new life. “So what we've been doing is not so much going into the high-end, brand-new standards like VPX, [a new embedded computing architecture that supports 6.25 gigabits/sec of throughput], and things like that. Instead, we just integrate higher computing power FPGAs and controllers and build into the FPGAs things like hard-core Power PC computing engines, with multiple Gigabit Ethernet devices already built in. And then around that, we provide essentially customized FPGA solutions built on those capabilities to create a slave or master computing element within their [system's] architecture.”

In the case of a system used to control infrared sensors aboard Coast Guard-operated P-3 Orion patrol aircraft, Van Doren's group reverse engineered and replaced one entire VME circuit board. “They didn't want to replace the entire night imaging system that's being used for border security patrols, for drug interdiction and border security,” he said. “So instead of having to replace that system, we replaced one out of the 10 cards in that rack. For about a $100,000 [non-recurring engineering] task and then less than $10,000 per board, they get to keep that system up and running. Replacement would probably be close to five million dollars. That's typical for what we provide.”